Do you remember your elementary school teacher demonstrating the principle of diffusion? She took an eyedropper and squeezed a drop of red food dye into a glass of clear water. In seconds the water was tainted with a pinkish hue. To be a cultural Christian in your parents’ generation was to be like a clear glass of water with one drop of red dye. In other words, secular culture was not that different from Christian culture. That was before Internet pornography, abortion on demand, explicit sex during prime-time TV, and the like. To be a cultural Christian today is like having the whole bottle of red dye poured in the glass.